// The MIT License (MIT)
//
// Copyright (c) 2019 Hellobike Group
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.

import 'package:flutter/widgets.dart';

extension ThrioStatefulWidget on StatefulWidget {
  /// Get widget state from the global key.
  ///
  /// Throw `Exception` if the key is not a GlobalKey<T>.
  ///
  T stateOf<T extends State<StatefulWidget>>() {
    if (this.key == null) {
      return null;
    }
    final key = this.key;
    if (key is GlobalKey<T>) {
      return key.currentState;
    }
    throw Exception('${key.runtimeType} is not a GlobalKey<T>');
  }

  /// Get widget state from the global key.
  ///
  T tryStateOf<T extends State<StatefulWidget>>() {
    if (this.key == null) {
      return null;
    }
    final key = this.key;
    if (key is GlobalKey<T>) {
      return key.currentState;
    }
    return null;
  }
}
